9424200994 Rev N 123
Power (32) Protection
Two power (32) elements monitor three-phase real power (watts). An element can be configured to
protect against overpower or underpower conditions.
The two, identical power protection elements are designated 32-1 and 32-2. Element logic connections
are made on the BESTlogic™Plus screen in BESTCOMSPlus® and element operational settings are
configured on the Power settings screen in BESTCOMSPlus. A summary of the logic inputs and outputs
and operational settings appears at the end of this chapter.
BE1-11g protection systems enabled for IEC-61850 communication
(style Gxxxx5xxxxxxxx) have their power protection elements fixed at
one overpower element and one underpower element.
BESTCOMSPlus Navigation Path: Settings Explorer, Protection, Power, Power (32)
HMI Navigation Path: Settings Explorer, Protection, Settings Group x (where x = 0 to 3), Power
Protection, Power 32
Element Operation
Power protection can be used in applications where excessive power flow in the tripping direction is bad.
Overpower and/or underpower protection is desirable in applications where:
• Power flows into a generator, indicating loss of prime mover torque (motoring).
• Power flows into the secondary of a station distribution transformer, indicating an industrial or
private customer is supplying power into the utility system.
• Excessive load has been connected to a system.
• Overload has been placed on a distribution system.
• Overspeeding is a prime concern.
• An open breaker creates an overload on a local generation facility.
Mode
In Total Power mode, if total power is above or below pickup, and in the set direction, the element will pick
up. In modes 1 of 3, 2 of 3, or 3 of 3, a single-phase power pickup value is automatically calculated based
on the three-phase power setting. If the single-phase power is above or below the calculated pickup value
(1 of 3, 2 of 3, or 3 of 3) and in the set direction, the element will pick up. The element will remain in the
picked-up condition until power flow falls below the dropout ratio of 95% of the actual pickup.
To clarify the difference between 3 of 3 and Total Power modes, assume that 3 of 3 mode has been
selected and the three-phase pickup setting is 30 watts. Therefore, the BE1-11g will pick up when each
phase exceeds 10 watts (three-phase setting/3). Alternately, if two phases are zero (0) watts and the third
phase is 50 watts, the BE1-11g will not pickup because two of the phases have not exceeded the single
phase pickup threshold required for 3 of 3 operation. All three phases must exceed the single-phase
pickup threshold for operation to occur. However, if the 32 element was set for Total Power mode, the
same power values previously mentioned would result in a pickup condition because “Total Power” (0 + 0
+ 50 watts) exceeds the three-phase pickup setting of 30 watts. For details on power calculations, refer to
the Configuration chapter.
BE1-11g Power (32) Protection
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